No abstract

In this work, two-dimensional and three-dimensional simulations on the flow in a room coupled with a facade of passive heating system type In-In (Trombe wall) were conducted numerically to determine the temperature and velocity fields in the influence of the variation of the modified Rayleigh number, which itself depends on the characteristics of the fluid and heat flow due to sunshine. The behavior of boundary layers in natural convection is analyzed along the Trombe wall in our periodically heated imposed flow. Thermal and dynamics modeling of the problem were made by a computational fluid dynamics (CFD) calculation, based on the finite volume method to model both the fluid flow and heat transfer. To take account of the strong temperature gradient and velocity near the walls, we chose a structured tight mesh near the walls and a little wider mesh elsewhere. The results have shown that for Grh > 4 × 108, the flow regime is laminar, while for Grh > 109, the flow regime becomes turbulent.

In this present work, simulations were carried out numerically to characterize a porous material. The basic equations, which govern this problem, are those of the Navier-Stokes equations coupled with the Darcy equation. In order to understand the phenomena at stake, a first test was first completed on the independence of the mesh compared to the numerical solution obtained, the second test is devoted to the validation of Darcy (Re <<1). The characterization of the material is based on physical tests; the first is devoted to the porosity of the material, the second to the thickness, and the trireme to the saturation. The results are presented on the one hand contours for the velocity fields and streamlines, and on the other hand, are illustrated with curves to interpret the physical parameters studied in relation to each other.